Tuning the molar mass of P3HT via direct arylation polycondensation yields optimal interaction and high efficiency in nonfullerene organic solar cells. Issue 35 (8th June 2021)

• Record Type: Journal Article
• Authors: Liu, Yang; Xian, Kaihu; Peng, Zhongxiang; Gao, Mengyuan; Shi, Yibo; Deng, Yunfeng; Geng, Yanhou; Ye, Long
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 35(2021)
• Page Start: 19874
• Page End: 19885
• Publication Date: 2021-06-08
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta02253a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The application and the molar mass dependence of P3HT via direct arylation polycondensation are explored in fullerene-free solar cells. The medium molar mass batch delivered a top efficiency of ∼10%. Abstract : Due to the simple structure and excellent scalability, regioregular poly(3-hexylthiophene) (P3HT) has become much more popular as a low-cost donor polymer partner with the emerging nonfullerene acceptors in recent years. Presently, the application and the molar mass dependence of direct arylation polycondensation (DArP) prepared P3HT in fullerene-free organic solar cells have not been explored yet. In this work, five batches of P3HT with weight-average molar mass ranging from 8.9 kg mol −1 to 89.1 kg mol −1 were successfully prepared via DArP, with the aim to detail the interaction–performance relationships in the state-of-the-art P3HT:nonfullerene photovoltaic blend, namely P3HT:ZY-4Cl. Our thermodynamic analysis revealed that the amorphous–amorphous interaction parameters strongly depend on the P3HT molar mass and can be varied by a factor of 2.75. Owing to the best π–π stacking order deduced from grazing incidence X-ray diffraction and the smallest domain size, the blend based on the medium molar mass batch (25.5 kg mol −1 ) delivered the highest current density, fill factor, and power conversion efficiency up to ∼10% among the five systems. Our study confirmed that DArP is an effective protocol for the synthesis of P3HT for efficient non-fullerene polymer solar cells and the established relationships can be applied to screen the best batch for P3HT-based organic photovoltaics.